Implemented changes for async server deletion
Added rspec tests for async server deletion
Use latest azure service delete api to run knife azure server delete in background
Implemented review comments to update query_azure for async request and changes for code cleanup
Fixed and added rspec tests for async server delete changes
Implemented changes for async server deletion
Added rspec tests for async server deletion
Use latest azure service delete api to run knife azure server delete in background
Fixed and added rspec tests for async server delete changes
Merge pull request #121 from opscode/adamed-oc-10567

OC-10567: knife azure server delete should be asynchronous by default